BRIDGETON, N.J. (CBSNewYork) – As the days continue to go by since 5-year-old Dulce Maria Alavez vanished from a park in Cumberland County, the FBI is now offering a reward of up to $5,000 for information leading to her being found – bringing the total for her recovery to a combined $20,000.

An Amber Alert has been issued and investigators say they believe she was abducted.

The girl disappeared from Bridgeton City Park on Monday afternoon, and her family is desperate to have her home.

Dulce was last seen between 4 p.m. and 5 p.m. on Monday afternoon at the park’s playground. She was with her 3-year-old little brother, while her 19-year-old mother Noema Alavez Perez was in her car with another family member about 50 yards away.

Help us locate Dulce Maria Alavez, age 5! The #FBI is offering a reward of up to $5,000 for information that leads to her whereabouts. Please contact the FBI's Toll-Free Tipline at 1-800-CALL-FBI and select option 4, then select option 8.https://t.co/yVIE6Np2Iqpic.twitter.com/psCQDhiMg6

The first 30 hours after the girl’s disappearance, police conducted a full-scale search of the park and nearby waterways. At the same time detectives launched a criminal investigation which led them to conclude the girl was abducted.

“We have not been able to eat or sleep,” said the girl’s grandmother through a translator. “You can’t imagine what we are going through. We are very sad, please help our family.”

“We are pursuing all leads,” said Cumberland County Prosecutor Jennifer Webb-McRae. “We are pursuing all leads, we are focusing our efforts in and around the area of the park.”

At least one witness was able to provide details about a possible kidnapper.

Police are not sure if the suspect knows young Dulce or not. They say the girl’s father is not in the United States and the rest of the victim’s family is cooperating.

Police describe their suspect as light-skinned, 5-foot 6-inches to 5-foot 8-inches tall, with no facial hair and acne. He was last seen in orange sneakers, red pants and a black shirt. Investigators are also looking for a red van with sliding doors and tinted windows.

Anyone with information is asked to call the Bridgeton Police Department at 856-451-0033 or text anonymously to TIP411.